The Atypical Rho GTPase Wrch1 Collaborates with the Nonreceptor Tyrosine Kinases Pyk2 and Src in Regulating Cytoskeletal Dynamics
| Autor: | Pontus Aspenström, Aino Ruusala |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Protein Conformation
Swine Proto-Oncogene Proteins pp60(c-src) CDC42 GTPase Biology Kidney Transfection Cell morphology Cell Line Focal adhesion Mice Pregnancy Two-Hybrid System Techniques Animals Humans Pseudopodia RNA Small Interfering cdc42 GTP-Binding Protein Cytoskeleton Molecular Biology Aorta Cells Cultured Mice Knockout Endothelial Cells Articles Cell Biology Fibroblasts Immunohistochemistry Cell biology Focal Adhesion Kinase 2 Cdc42 GTP-Binding Protein Mutation Female Endothelium Vascular Filopodia Plasmids Proto-oncogene tyrosine-protein kinase Src |
| Zdroj: | Molecular and Cellular Biology. 28:1802-1814 |
| ISSN: | 1098-5549 |
| DOI: | 10.1128/mcb.00201-07 |
| Popis: | The Cdc42-like GTPase Wnt responsive Cdc42 homolog 1 (Wrch1) has several atypical features; it has an N-terminal proline-rich extension that confers binding to SH3 domains, and it harbors an extremely high intrinsic nucleotide exchange activity, which overrides the normal GTPase activity. As a result, Wrch1 resides mainly in the active, GTP-loaded conformation under normal cellular conditions. We have previously shown that ectopic expression of Wrch1 in fibroblasts resulted in an altered cell morphology visible as a formation of filopodia, a loss of stress fibers, and a reduction in focal adhesions. Here, we show that Wrch1 binds to the nonreceptor tyrosine kinase Pyk2. The interaction required Wrch1 to be in a GTP conformation and also required an intact N-terminal proline-rich extension as well as an intact effector loop. Wrch1 requires Pyk2 in imposing the cytoskeletal effects, seen as the formation of filopodia, since treatment of cells with a Pyk2-specific small interfering RNA abrogated this response. Interestingly, we found that the presence and activity of Src were needed for the formation of a Wrch1-Pyk2 complex as well as for the Wrch1-induced formation of filopodia. We propose a model in which Pyk2 and Src function to coordinate the Wrch1-dependent effects on cytoskeletal dynamics. |
| Databáze: | OpenAIRE |
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